/////////////////////////////////////////////////////////////////////
//
// Unix getopt(3)
//
// File:   getopt.c
//

#include <stdio.h>
#include <io.h>
#include <string.h>

/*
 * Here's something you've all been waiting for:  the AT&T public domain
 * source for getopt(3).  It is the code which was given out at the 1985
 * UNIFORUM conference in Dallas.  I obtained it by electronic mail
 * directly from AT&T.  The people there assure me that it is indeed
 * in the public domain.
 *
 * There is no manual page.  That is because the one they gave out at
 * UNIFORUM was slightly different from the current System V Release 2
 * manual page.  The difference apparently involved a note about the
 * famous rules 5 and 6, recommending using white space between an option
 * and its first argument, and not grouping options that have arguments.
 * Getopt itself is currently lenient about both of these things.  White
 * space is allowed, but not mandatory, and the last option in a group can
 * have an argument.  That particular version of the man page evidently
 * has no official existence, and my source at AT&T did not send a copy.
 * The current SVR2 man page reflects the actual behavor of this getopt.
 * However, I am not about to post a copy of anything licensed by AT&T.
 */

#if 0
#define ERR(s, c)\
  if(opterr){\
        char errbuf[2];\
        errbuf[0] = (char)c; errbuf[1] = '\n';\
        (void) write(2, argv[0], (unsigned)strlen(argv[0]));\
        (void) write(2, s, (unsigned)strlen(s));\
        (void) write(2, errbuf, 2);\
  }
#else
#define ERR(s, c) if (opterr) printf("%s: %s%c\n", argv[0], s, c)
#endif

int     opterr = 1;
int     optind = 1;
int     optopt = 0;
char    *optarg = 0;

int
getopt(argc, argv, opts)
int     argc;
char    **argv, *opts;
{
        static int sp = 1;
        register int c;
        register char *cp;

        if(sp == 1)
                if(optind >= argc ||
                   argv[optind][0] != '-' && argv[optind][0] != '/' ||
                   argv[optind][1] == '\0')
                        return(EOF);
                else if(strcmp(argv[optind], "--") == 0) {
                        optind++;
                        return(EOF);
                }
        optopt = c = argv[optind][sp];
        if(c == ':' || (cp=strchr(opts, c)) == 0) {
                ERR(": illegal option -- ", c);
                if(argv[optind][++sp] == '\0') {
                        optind++;
                        sp = 1;
                }
                return('?');
        }
        if(*++cp == ':') {
                if(argv[optind][sp+1] != '\0')
                        optarg = &argv[optind++][sp+1];
                else if(++optind >= argc) {
                        ERR(": option requires an argument -- ", c);
                        sp = 1;
                        return('?');
                } else
                        optarg = argv[optind++];
                sp = 1;
        } else {
                if(argv[optind][++sp] == '\0') {
                        sp = 1;
                        optind++;
                }
                optarg = NULL;
        }
        return(c);
}
